-LRB- CNN -RRB- -- The sudden death of Academy Award-winning actor and comedian Robin Williams has sent shock waves throughout the world . The 63-year-old was not only known for bringing laughter to so many throughout his career but for bringing compassion to his philanthropic causes as well .

Impact Your World remembers Williams ' generosity by looking at some charities with which he worked .

Robin Williams ' legacy : A big heart for charity

The United Service Organization -LRB- USO -RRB- was a perfect fit for the comedian . The goal of the organization is to lift the spirits of American troops , and that 's exactly what Williams did . During his USO tours , the `` Good Morning , Vietnam '' star traveled to war zones entertaining troops from Afghanistan to Kuwait .

The Christopher & Dana Reeve Foundation , which is dedicated to curing spinal cord injuries , tweeted :

The entertainer and Christopher Reeve were very close friends . They formed an inseparable bond as roommates while studying at New York 's Julliard School .

Williams was the first to bring a smile to his college buddy 's face after Reeve 's 1995 horseback riding accident left him paralyzed from the neck down . In Reeve 's autobiography `` Still Me , '' he wrote how Williams made a surprise hospital visit impersonating a Russian proctologist and was going to perform an exam on him !

The comedic actor was a friend to people of all ages .

Just like his `` Patch Adams '' character , Williams brought smiles and laughter to sick children . He visited kids battling cancer one-on-one and signed autographs at St. Jude Children 's Research Hospital .

In 2006 , the father of three was honored with the Muhammad Ali Humanitarian Award at Celebrity Fight Night . The annual event raises money primarily for the Muhammad Ali Parkinson Center in Phoenix . Reba McEntire has emceed the benefit dinner and auction for the past nine years and recalled her favorite memory of Williams .

She added , `` I will miss Robin so much , as we all will . Thank God we have so many wonderful memories of him , his wit , talent , big heart and generosity . ''

The late actor was also involved with Comic Relief to raise money for those in need , especially America 's homeless .

He hosted a series of HBO TV specials with comedian friends Billy Crystal and Whoopi Goldberg .

Comic Relief founder Bob Zmuda remembered Williams ' generosity on CNN 's `` New Day '' : `` Robin was the one from the get-go that was really insistent that we would raise funds for the homeless community . Robin was kind of born with a silver spoon in his mouth . ... I think he felt that he was given so much and that he needed to give back and he truly did . ''

Complete coverage of Robin Williams

Videos : The world according to Robin Williams

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Robin Williams was involved in several charitable causes

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He toured with the USO and volunteered with St. Jude Children 's Hospital

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The comedian also served on the board of The Christopher & Dana Reeve Foundation